1. Field of Invention
The invention relates to stands for holding Christmas trees, either real or artificial, in a stable, essentially vertical position for decorating and display.
2. Description of Prior Art
Even though putting up and decorating the Christmas tree is only a once-a-year activity, the "putting-up" part is traditionally an annoyingly frustrating task, because prior art tree stands have not been designed to make the job easy. The reason it's so difficult with prior art tree stands is because the same screws that are used to attach the stand to the tree are also used to adjust the tree to a vertical position.
Depending on the particular tree stand used, the number of screws requiring adjustment can be anywhere from three to eight. Moreover, real Christmas trees vary considerably in trunk size depending on tree height and species selected as well as random variations from tree to tree, and the multiplicity of screws can require considerable adjustment time. Also, one or more of the adjusting screws frequently can encounter knots or bulges which cause the screw to be off center, which can result in the tree not being held firmly by the stand. Additionally, the small diameter screws that are used penetrate the tree trunk, making it even more difficult to align the tree to vertical.
The adjustment process traditionally requires one person to lie under the tree and try various adjustment combinations, while others watch the effects and offer suggestions regarding verticality. And when the job is done--usually by mutual consent that "it's close enough"--what's left is a tree that's not very securely attached to a stand that in itself is not a very stable or rigid platform.
And frequently the small loads placed on the tree while it's being decorated will shift it off of its near-vertical far enough to require another round of readjustment.
Present commercially available tree stands also contribute to the problem of inadequately watered trees. The most popular stands feature shallow basins to hold water which quickly evaporates in the warm, low humidity air within the room. Further, the amount of water can only be determined by again lying on the floor to view or feel the status of the basin. And because there is no water level indicator, filling frequently results in overfilling.
In response to these well recognized problems a plethora of solutions have been proposed over the years.
U.S. Pat. No. 2,905,414, issued to Zierden on Sep. 22, 1959, discloses a four point anchoring system with a pin at the base to hold the trunk. The alignment/attachment screws feature rounded ends to prevent cutting into the tree and to accommodate variations in roundness of the tree trunk.
U.S. Pat. No. 4,825,586, issued to Coppedge on May 2, 1989, discloses another four point arrangement, in which magnets are proposed to hold clamping plates at the end of each adjustment/attachment screw.
Still another four point arrangement is disclosed in U.S. Pat. No. 4,967,508, issued to Reynolds on Nov. 6, 1990. A pad is shown connected to the adjustment/attachment screws via a ball and socket arrangement to permit motion between the pad and screw to accommodate the variations encountered with Christmas tree trunks sizes and shapes.
All of the above suffer from the same problem, that is, the multiple attachment screws are also used for adjusting the vertical positioning of the tree.
U.S. Pat. No. 4,901,971, issued to Connelly on Feb. 20, 1991, discloses a single point clamping mechanism utilizing an angled plate with a free-floating rectangular push plate. If a tree with a bulge occurring at a point substantially lower than the location of the screw on the push plate is encountered, it is evident that the screw/push plate arrangement will easily jam and the tree will not be held securely. In order to adjust the vertical position of the tree, the legs must be adjusted using four wing nuts holding two independently adjustable legs. Clearly, vertical adjustment cannot be accomplished while the tree is in the stand since the full weight of the tree will be borne by the adjusting wing nuts.
U.S. Pat. No. 1,694,815, issued to Garlick on Jun. 20,1922, discloses the use of thumb screws at different elevations to hold the trunk. Vertical adjustment is accomplished by adjustment thumb screws at the end of the supporting legs. Again, this adjustment must be done with the full weight of the tree bearing on the adjustment mechanism.
U.S. Pat. No. 4,436,272, issued to Lile et al. on Mar. 13, 1984, discloses the use of two opposing clamps. As in the Connelly disclosure, variations in tree trunk roundness can result in clamping plates to be applied unevenly thus causing the screws to jam. Vertical adjustment is accomplished by inconveniently located leveling feet at the ends of the supporting arms.
U.S. Pat. No. 4,913,395, issued to Juhas on Apr. 3, 1990, discloses a gimbaled bracket structure so that the tree can be adjusted vertically. Adjustment of the vertical positioning of the tree requires adjustment of four wing nuts which must all be tightened to hold the tree vertical. The legs of the stand are independent of the gimbals mechanism. Attachment of the tree requires tightening four eye bolts.
U.S. Pat. No. 5,000,414, issued to Rosato on Mar. 19, 1991, discloses a spring biasing means to firmly hold the tree in the stand. The spring biasing means also serves to adjust the vertical position of the tree which requires at least two people to adjust the vertical position of the tree.
U.S. Pat. No. 3,661,349, issued to De Vries on May 9, 1972, discloses another gimbals mechanism to position the tree. Again, two people are required to position the tree because one cannot lock one axis independently of the other one.
U.S. Pat. No. 2,605,067, issued to Lindsell on Dec. 1, 1950, discloses an elaborate gimbaled arrangement requiring the use of bearings, counterweight tensioning means and sockets for Christmas tree bulbs as well as a rotating function. This design is prohibitively expensive to manufacture. In addition, it uses a four point thumb screw attachment method to hold the tree within the stand.
A Christmas tree stand that is inexpensive to manufacture, that permits attachment of the tree to the stand by a single clamping mechanism and, independently, permits adjustment of the vertical alignment of the tree by a single person is not found in the prior art.